The present invention relates to an image-forming apparatus for forming an image on a long recording sheet wound in a roll, or a like state.
Conventionally, long recording sheets wound upon a core tube (hereinafter referred to as xe2x80x9crolled recording sheetxe2x80x9d) are used widely as the recording sheet for image formation with an image-forming apparatus. Usually, to feed the rolled recording sheet to the image-forming apparatus, a holder for holding the roll of the recording sheet is provided on the rear side of the main body of the image-forming apparatus. On the rear side, an inlet port is provided for feeding the rolled recording sheet from the holder. On the front side of the main body of the apparatus, an outlet port is provided for discharging the recording sheet after image formation. Between the inlet port and the outlet port, an image-forming zone is provided for image formation on the rolled recording sheet.
Between the inlet port and the image-forming zone, a pair of rollers are placed to pinch and deliver the rolled recording sheet to the image-forming zone. The roller pair consists of a driving roller and a driven roller placed above. The driven roller is made movable upward and downward to be coupled to or decoupled from the driving roller. A manipulating lever is provided near the outlet port to move the driven roller upward and downward. The rolled recording sheet is pinched by the driving roller and the driven roller and is delivered with rotation of the driving roller.
For image formation on the rolled recording sheet, the rolled recording sheet is delivered stepwise by the driving roller and the driven roller by one printing band width. After the formation of the one printing band portion of the image, the rolled recording sheet is delivered further by the one printing width. On the newly delivered portion of the recording sheet, a next printing band portion of the image is formed. Such operations are repeated to form the entire image. The rolled recording sheet is then delivered to be discharged from the outlet port.
When the rolled recording sheet held by the roll holder has been used up entirely or a like case, the core tube left on the holder is taken out, and a fresh recording sheet roll is set to the holder. Before formation of an image on this fresh rolled-recording sheet, the rolled recording sheet should be pinched between the driving roller and the driven roller. For pinching the recording sheet between the driving roller and the driven roller, firstly a manipulating lever is handled to displace the driven roller upward to be decoupled from the driving roller (Step 1); with the driven roller kept decoupled from the driving roller, the front end portion on the outermost face of the rolled recording sheet is introduced through the inlet port (Step 2); then the front end portion is inserted between the driving roller and the driven roller (Step 3); and finally the driven roller is lowered by handling the manipulating lever to press the driving roller through the rolled recording sheet (Step 4). Thus, the rolled recording sheet is pinched between the driving roller and the driven roller to be ready for delivery to the image-formation zone.
In the aforementioned operation for delivery of the fresh rolled recording sheet to the image formation zone, the user conducts the above Step 1 at the front side of the apparatus, thereafter the user moves to the rear side of the apparatus to practice the above Step 2 and Step 3, and further the user moves again to the front side of the apparatus again to practice the above final Step 4.
With conventional image-forming apparatuses, as described above, the user has to move between the front side and rear side of the apparatus for replenishment of the rolled recording sheet and delivery of the fresh rolled recording sheet to the image formation zone. This is inconvenient and inefficient in the operation.
Under the aforementioned circumstances, the present invention intends to provide an image-forming apparatus improved in operability.
For achieving the above object, a first embodiment of the image-forming apparatus of the present invention having a pair of rollers for pinching and delivering a recording sheet in a delivery direction toward an image-forming zone for image formation, the recording sheet being introduced from an inlet port placed at an upstream side of the pair of rollers against the delivery direction and being discharged from an outlet port placed at a downstream side of the image-forming zone along the delivery direction, the image-forming apparatus comprising
(1) a coupling unit for coupling and decoupling the pair of rollers, and
(2) a first manipulating member placed near the inlet port, and linked to the coupling unit for manipulating the coupling unit.
The image-forming apparatus may comprise
(3) a second manipulating member which is placed near the outlet port, and is linked to the coupling unit for manipulating the coupling unit.
The coupling unit may comprise
(4) a turning arm linked to both of the first manipulating member and the second manipulating member and being turnable in a prescribed direction and the reverse direction; and
(5) a coupling member linked to the turning arm, for decoupling the pair of rollers by turning the turning arm in the prescribed direction and coupling the pair of rollers by turning the turning arm in the reverse direction.
The image-forming apparatus may comprise
(6) a third manipulating member, instead of the first manipulating member, formed in integration with the turning arm, and placed near the inlet port.
A second embodiment of the image-forming apparatus of the present invention having a coupleable rollers for pinching and delivering a recording sheet in a delivery direction toward an image-forming zone for image formation, the recording sheet being introduced from an inlet port placed at an upstream side of the pair of rollers against the delivery direction and being discharged from an outlet port placed at a downstream side of the image-forming zone along the delivery direction, the image-forming apparatus comprising
(7) a manipulating member taking either a coupling position for coupling the pair of rollers or a decoupling position for decoupling the pair of rollers and being energized to take the coupling position, for manipulating the pair of rollers;
(8) a turning arm linked to the manipulating member to be, turnable;
(9) a coupling member linked to the turning arm to decouple the pair of rollers with the manipulating member set at the decoupling position and to couple the pair of rollers with the manipulating member set at the coupling position; and
(10) a first locking means placed near the inlet port for locking the turning arm not to turn with the manipulating member set at the decoupling position.
The image-forming apparatus of the second embodiment may comprise
(11) a releasing means placed near the inlet port for releasing the turning arm from locking by the first locking means.
A third embodiment of the image-forming apparatus of the present invention having a pair of coupleable rollers for pinching and delivering a recording sheet in a delivery direction toward an image-forming zone for image formation, and the recording sheet being introduced from an inlet port placed at an upstream side of the pair of rollers against the delivery direction and being discharged from an outlet port placed at a downstream side of the image-forming zone along the delivery direction, the image-forming apparatus comprising
(12) a first manipulating member placed near the inlet port for coupling and decoupling the pair of rollers;
(13) a second manipulating member placed near the outlet port for coupling and decoupling the pair of rollers;
(14) a turning arm linked to both of the first manipulating member and the second manipulating member and being turnable in a prescribed direction and the reverse direction;
(15) a coupling member linked to the turning arm, for decoupling the pair of rollers by turning the turning arm in the prescribed direction and coupling the pair of rollers by turning the turning arm in the reverse direction;
(16) a second locking means for locking one of the first manipulating member and the second manipulating member when the pair of rollers are coupled.
(17) The second locking means may be an openable cover which is openable at an upper part of the main body of the image-forming apparatus, and the openable cover prevents turn of the first manipulating member or the second manipulating member to lock the manipulating means when the openable cover is closed.
A fourth embodiment of the image-forming apparatus of the present invention having a driving roller for delivering a recording sheet in a delivery direction toward an image formation zone, a turnable arm extending in a direction nearly parallel to the delivery direction above the driving roller, and a driven roller fixed rotatably to the turnable arm and capable of coupling with the driving roller, the recording sheet being introduced from an inlet port placed at an upstream side of the driving roller against the delivery direction and being discharged from an outlet port placed at a downstream side of the image-forming zone along the delivery direction, the image-forming apparatus comprising
(18) a turnable shaft extending in a direction crossing the turnable arm above the driven roller;
(19) a bearing for supporting one end of the turnable shaft;
(20) a pushing cam which pushes the turnable arm with turn of the turning shaft in the prescribed direction to lift the driven roller above the driving roller, and couples the driven roller with the driving roller with turn of the turning shaft in the direction reverse to the prescribed direction;
(21) a turning arm lever having a connecting end connected to the other end of the turning shaft, a turning arm extending downward from the connecting end in a direction approximately perpendicular to the turning shaft, and a third lever extending from the connecting end to vicinity of the inlet port at the upstream side against the delivery direction;
(22) a second arm having a first end connected to a bottom end of the turning arm, and a second end placed downstream after the first end along the delivery direction; and
(23) a second manipulating member having a turning end fixed in a turnable manner near the outlet port and connected to the second arm at the second end.
A fifth embodiment of the image-forming apparatus having a driving roller for delivering a recording sheet in a delivery direction toward an image formation zone, a turnable arm extending in a direction nearly parallel to the delivery direction above the driving roller, and a driven roller fixed rotatably to the arm and capable of coupling with the driving roller, the recording sheet being introduced from an inlet port placed at an upstream side of the driving roller against the delivery direction and being discharged from an outlet port placed at a downstream side of the image-forming zone along the delivery direction, the image-forming apparatus comprising
(24) a turnable shaft extending in a direction crossing the arm above the driven roller;
(25) a bearing for supporting one end of the turnable shaft;
(26) a pushing cam which pushes the arm with turn of the turning shaft in the-prescribed direction to separate the driven roller upward from the driving roller, and couples the driven roller with the driving roller by turn of the turning shaft in the direction reverse to the prescribed direction;
(27) a turning arm having a upper end connected to the other end of the turning shaft and extending downward from the upper end in a direction approximately perpendicular to the turning shaft and being turnable around the upper end;
(28) a protrusion formed at the bottom end of the turning arm to protrude therefrom;
(29) a second arm having a first end connected to a lower end of the turning arm, and a second end placed downstream after the first end along the delivery direction;
(30) a second manipulating member having a turning end fixed in a turnable manner near the outlet port and connected to the second arm at the second end;
(31) a pulling coil spring which is placed in the upstream before the second manipulating member pulls the second manipulating member in the upstream direction against the delivery direction to energize the turning arm to turn in the reverse direction; and
(32) a stopper which is placed near the inlet port and locks the turning arm by hooking the protrusion of the turning arm when the turning arm is turned in the prescribed direction.
The image-forming apparatus of this embodiment may be provided with
(33) a stopper-releasing device, and
(34) a releasing device controller for controlling the stopper-releasing device.